It also affirmed the assault conviction of Philemon Chavis, who severely beat his wife on a city street and then held her for ransom.

Vanderhorst, 19, is serving a 25-year sentence at maximum-security Five Points Correctional Facility in Seneca County for first-degree manslaughter.

Rhodes, a track star at Albany High School, died after Vanderhorst stabbed him once in the heart on April 30, 2011. A teenager videotaped the killing on a cellphone, creating the key evidence for prosecutors in the trial.

Vanderhorst appealed, citing lack of evidence presented to support a conviction, that records of impassioned 911 calls should not have been played for the jury and insufficiency of counsel.

Justices of the Appellate Division of state Supreme Court denied the appeal on all points and cited the convincing evidence shown on the cellphone video in making their decisions.

"The victim can be heard early in the encounter asking defendant to put the knife down and 'give me a fair one,' and onlookers are heard repeatedly calling defendant's name and urging him to stop, fight with his hands, and put down the knife," justices wrote in the decision. "At several points in the altercation, bystanders attempted unsuccessfully to pull defendant away from the victim or step between them."

In the Chavis case, the defendant appealed on the grounds that he was not mentally competent to stand trial. Justices ruled he did not preserve that issue, or put it on the record during his plea.

At his August 2011 sentencing, Chavis received 19 years in prison for savagely attacking his wife five months earlier. She described how he became a "runaway freight train speeding down a hill with no brakes" during her victim impact statement.

On March 13, Chavis slammed the head of Karen Chavis, his wife of 25 years, into concrete inside their renovated carriage house at 22 Garden Alley. He punched her, choked her to unconsciousness and doused her with bleach. Then he tied her up in a luxury car and forced her to try to extract a $100,000 ransom from her family or face death.

Chavis, a 47-year-old former state public works investigator for the state Department of Labor, was quickly arrested for the attack, which nearly killed his wife.